The effects of verbal and spatial interference in the encoding and retrieval of spatial and nonspatial texts

The paper investigates the specific roles of visual–spatial working memory (VSWM) and verbal working memory (VWM) in encoding and retrieval of information conveyed by spatial and nonspatial texts. In two experiments, a total of 109 undergraduate students—54 in Experiment 1, 55 in Experiment 2—listened to spatial and nonspatial texts while performing a spatial (Experiment 1) or verbal (Experiment 2) concurrent task during either encoding or retrieval. Text memorisation and comprehension were tested by free-recall and sentence-verification tasks. The results show that a concurrent spatial task is detrimental to memory performance for spatial text more than for nonspatial text. In contrast, a concurrent verbal task is equally damaging to memory performance for both spatial and nonspatial texts. Moreover, a spatial task interferes with both encoding and retrieval, in contrast with a verbal task, where the interference effect is active only when the task is performed during encoding. Overall, these findings show the involvement of VSWM in the construction and reactivation of mental models derived from spatial descriptions, and the role played by VWM in construction, but not reactivation, of mental models derived from spatial and nonspatial texts.